Nowadays, a large variety of electronic devices is used in many different power and voltage ranges. Such electronic devices often use semiconductor devices in order to implement various electric circuits. These semiconductor devices may resist a voltage of only several Volts or also up to several thousand Volts. Devices with high-blocking voltage (e.g. several thousand Volts) often use bipolar power transistors to switch such large voltages. Bipolar power transistors often comprise a low doping of the collector zone in order to implement their blocking capability. For example, the second breakdown may be avoided by strong limitation of the current density in forward direction (e.g. about 30 A/m2 for a power bipolar junction transistor with a blocking voltage of 4.5 kV). The increase of the blocking voltage and/or the maximal current density of electronic devices is an ongoing desire.